Tensile-strength tester.



S. N. SENNA.

TEN'SILE STRENGTH TESTER.

APPLICATION FILED DEC. 5, 1914.

2 SHEETSSHEET l.

WITNESSES: F E 2 IN VEN TOR.

BY 1 127 W I g A TTORNEYS.

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SAMUEL-N. SENNA, F I-IOLYOKE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO CHARLES E. TOBRANCE,

OF HOLYOKE, MASSACHUSETTS.

TENSILE-STRENGTH TESTER.

Specification of Letters Patent.

Patented Feb. 29, 1916.

Application filed December 5, 1914. Serial No. 875,718.

To all whom it may concern Be it known that I, SAMUEL N. SENNA, a citizen of the United States of America, residing at Holyoke, in the county of Hampden and State of Massachusetts, have Invented a new and useful Tensile-Strength Tester,'of which the following is a specifica- 7 tion. 7 My invention relates to improvements in machines designed to test the tensile strength of sheet materials, such as'paper, fiberboard,

- means or mechanism to operate the clamping and rupture-producing partsand members, together with such other elements as may be necessary or the machine and render it practicable and eflicient in all respects.

Speed variation and clamping variation are the two most common sources of inaccuracy in a tester of the class hereinbefore referred to, and the primary objects of my invention are to eliminate entirely these two sources of inaccuracy, and to produce a machlne which, although in construction and operation, is absolutely reliable in the work done by it, being equipped with positive, constant-speed, driving mechanism, andwith means for always producing a uniform clamping pressure of great force. A sample being tested in this machine, if the latter be properly constructed and adjusted, can not by any possible chance crawl and so spoil the test or render it inaccurate.

The springing of a tester frame is frequently responsible for crawling on the part of the sample and an unreliable test, where fore I prefer to employ inmy tester a frame of the punch type, which can not spring or get out of alinement, but is always rigid and stable.

A further object is to provide adequate desirable to complete comparatively simple and convenient means of control for the machine, so that the person using said machine can make his tests easily and expeditiously.

It should be stated here, too,fthat the machine as a whole lends itself to speed and possesses greatly increased facilities for making tests, in addition to the feature of accuracy which characterizes said machine. Other objects and advantages will appear in the course of the following description.

Apreferred form or embodiment of the invention, whereby I attain the objects and secure the advantages of the same, is illustrated in the accompanying drawings, and I will proceed to describe the invention with reference to said drawings, although it .is to be understood that the form, construction, arrangement, etc. of the parts in various aspects are not material and may be modified without departure from the spirit of the invention. i

In the drawings, in which like numerals designate like parts throughout the several views, Figure 1 is atop plan of a tester which embodies my invention as aforesaid; Fig. 2, a side elevation of said tester, the upper portion of the gear-case, together with theworm-gear therein, being broken off, Fig. 3, a longitudinal central vertical section through the tester, taken on lines 33,,looking in the direction of the associated arrow, in Fig. 1; Fig. 4, a central vertical section through a modified form of perforating V plunger; Fig. 5, a fragmentary section showing a changed positionor relocation of the clamping spring, and, Fig. 6, an isometric view of the rear end of the cam shaft.

The four last views are on a larger scale than the two first views.

In the present embodiment of the tester, a support or frame 1 is provided, and this is mounted on and rigidly attached to a base plate 2, which latter may be securely fastened to any suitable supporting medium. I prefer to employ an electric motor 4 with which to operate the tester, and I mount such motor securely on a support 5 which in turn is mounted on and rigidly attached to the plate 2. The front end of the frame 1 is recessed at 6 to afford ample clearance for the material while being tested, as will presently more clearly appear. The frame 1 at the front end is bored vertically to form a chamber or cylinder 7 capable of containing a hydraulicelement. The'cylinder 7 opens at the top into the recess 6, and at the bottom, by way of a small horizontal passage 8, through the front side of said cylinder.

A gage to register the bursting pressure in pounds per square inch is attached to top of the frame for a horizontal shaft 11,

and ordinary caps 1212 are bolted to said boxes over said shaft.

The motor 4 has a shaft 13 which extends beneath the rear terminal portion of the shaft 11 and at right-angles to said shaft 11.

Secured on the motor shaft 13 directly under the shaft 11 is a worm 14.

Intermeshing with the worm 14 is a wormgear 15 which is loosely mounted on the shaft 11 behind the plane of the rear end of the frame 1. I

A housing 16, which is bracketed at 17 to the back end of the frame 1, is provided for the worm 14, and rising from said housing is a gear-case 18 for the worm-gear 15. The housing and gear-case are of the usual type, being made in two sections and bolted or screwed together.

Before proceeding to describe in further detail the driving mechanism of the machine, of which the worm 14 and the wormgear 15 are important elements, I will take up the clamping and testing or rupturing members at the front end of said machine,

the cylinder 8 and in a measure the head 9' being included with said members.

Having reference more particularly to Fig. 3, it will be observed that a hollow plunger 19 fits within the cylinder 7 and extends above said cylinder, and' that said plunger has an exterior flange at the top to form a clamping or sample-receiving and holding table 20, furthermore, that there is a solid plunger 21 within said plunger 19 and adapted to project or to be projected above the upper surface of said table. The hollow plunger 19 is the clamping plunger and the plunger 21 the perforating or puncturing plunger, as will presently be made plain. The bottom of the plunger 19 is packed at 22, the packing being held in place by a hollow nut 23 tapped into the base of said plunger. An annular shoulder 24 is located in the plunger 19 a short distance above the bottom thereof, and the plunger circular area of the noseof the plunger 21 is usually equal to one square inch.

A heavy calibrated spiral spring 27 encircles the lunger 19 between. the top of the cylinder? and the underside of the table or flange 20, and said flange with said plunger is supported by said spring at all times. The

fluid in the cylinder 7 under the plungers 19 and 21 is not high enough, when the parts are at rest or inactive, to support or elevate said plunger 21. Normally the spring 27 is in its approximately fully expanded con dition or inert. As will presently appear,

this spring is of such capacity as to insure a suitable clamping pressure, which is always uniform, before the test begins.

As shown in Fig. 5, the clamping spring 27 may be placed in the fluid chamber 7 between the floor of said chamber and the bottom of the clamping plunger 19, the effect or result being practically the same in this as in the other case.

In Fig. 4, a puncturing plunger 21, which is cored out or chambered at 28, is represented "in section. The hollow plunger is lighter than the solid plunger and better adapted for making tests on very thin or weak material. A plug 29 is inserted in the bottom of the chamber 28 to receive the packing screw 29.

A. circular plate or clamp 30 is provided to cooperate with the clamping plunger and table below, such clamp being secured to a tripod 31, which in turn is attached to a vertically reciprocating rod 32 that operates in the head 9. The clamp 30 is at the bottom of the tripod 31. The tripod 31 has an internally screwthreaded head 33 to receive the lower terminal of the rod 32, which is externally screw-threaded. Thus the clamp 30 may be vertically adjusted to increase or decrease the normal space between it and the table 20, and so to accommodate the parts to any thickness of material to be tested. A set-nut 34 is used on the rod 32, above the tripod head 33, to prevent the parts from working loose after adjustment. The

rod 32 is equipped with a roller or follower 35, such follower being mounted on a horizontal spindle 36 set in a yoke 37 at the top of said rod. An eccentric or cam 38 is secured on the front terminal of the shaft 11, which terminal projects beyond the front end of the frame 1 over the'rod 32, and a spring 39 encircles said rod between the head 9 and the yoke 37, the oifice of this spring being to force said rod upwardly and retain the follower 35 at all times in contact with said cam. Initially the cam 38 is disposed with its low part in contact with the follower 35. A bolt 40 may be employed to prevent the rod 32 from turning, said bolt being tapped into, the head 9 and having its inner end in a longitudinal slot 41 in said rod. The slot 41 must be long enough to enable the rod 32 to travel the required distance in either direction without interference on the part of the bolt 40. The cam 38 has a throw that is sulficient to insure adequate clamping pressure before the test actually occurs. The adjacent faces or surfaces of the clamp 30 and the table 20 are corrugated to enable them more firmly to grip the sample while the I test is being made.

The shaft 11 is held against endwise movement by the cam 38 and a collar 42,

both of which are secured on said shaft, and

the bearing-box 10 and its cap 12 which intervene between said cam and collar. A collar 43, which is secured on the shaft 11 immediately back of the gear-case 18, and

a collar 44, which is secured on said shaft immediately in front of the hub of the worm-gear 15, prevent said worm-gear from moving axially.

Extending forward from and integral with the hub of the worm-gear 15 is an annular clutch member 45. Mounted on the shaft 11, in front of the clutch member 45 and designed to engage and release the latter, is a hollow clutch member 46. The shaft 11 has a longitudinal passage 47 therein, which passage opens through the rear end thereof, and said shaft also has oppositelydisposed longitudinal slots in the sides thereof, one of which is shown at 48 in Fig. 3. The slots 48 are adjacent to the forward end of the clutch member 46, and open into the passage 47. A shipper rod 49 extends into and operates in the passage 47, and also projects beyond said passage. On the rear end of the rod 49 is a handle 50. A transverse pin 51 connects the rod 50 with the member 46, such pin passing through the slots 48 and operating therein. The slots 48 must be of suflicient length, as must also the passage 47, to enable the rod 49 and the pin 51 to be moved the necessary distance to throw the clutch out or in.. A spring 52 is interposed between the collar 44 and the closed end of the clutch member 46, within the two clutch members, and the tendency of said spring is to force said member 46 away from the member 45. The handle 50 is loosely mounted on the rod '49, but prevented from becoming detached therefrom by a screw 53 which passes through the -wardly to cause the member 46 to engage the member 45, and so retain said member 46 in engagement with said member 45. Slots 55 are cut in the back end of the shaft 11 to receive the fingers 54, when the clutch member 46 is released to the spring 52, and

thus to enable such release to take place, the handle 50 being turned on the rod 49 and the screw 53 at such time in order to move said fingers into line with said slots. The clutch is represented as being thrown out in Figs. 1 and 2, and as being thrown in in Fig. 3.

To throw in the clutch and start the machine, the handle 50 is grasped and moved rearwardly to draw more of the rod 49 from the shaft 11 and force the member 46, through the medium of the pin 51 and against the resiliency of the spring 52, into engagement with the member 45. The pin 51 is now in the rear ends of the slots 48..

ing the handle 50 when the parts are so positioned relatively that the fingers 54 en gage the extreme end of the shaft 11.

To throw out the clutch and stop the machine, hold or turn the handle 50 in such.

a way as to cause the fingers 54 to ride into the slots 55. This action releases the member 46 to the spring 52 and the latter actuates said member out of engagement with the member 45, the pin 51 then being moved forward in the slots 48 and the rod 49 being carried farther into the passage 47 The worm-gear 15 only stops when the current is shut off from the motor.

The driven parts revolve very slowly owing to the difference between the worm and the worm-gear.

In making a test the sample is placed on the table 20, while the follower 35 is in contact with the low part of the cam 38, and the clutch is thrown in unless already in. The cam 38 revolves and first forces the clamp 30'down onto the sample and the table 20, through the medium of the follower 35, the plunger 32 and the yoke 31, and against the resiliency of the spring 39. As the cam continues its revolution the clamp 30 forces the table 20 and the plunger 19 down against the resistance of the spring 27.. .Said spring being very strong and powerful offers suflicient resistance or causes the table 20 to offer suflicient resistance to the descending clamp to grip the sample between said table and clamp with a force that can not be broken, or from which the sample can not be loosened at any even the most minute point. The plunger 19, in being forced down farther into the cylinder 7, tends to compress or displace the fluid in said cylinder and force it up through the nut 23 and bottom of said plunger against the bottom of the plunger 21 or the packing 25, with the result that said last-mentioned plunger is forced upwardly against the sample over the opening in the table through which said plunger now protrudes, until, while the cam 38 is still rotating and before the high part thereof passes the follower 35, said plunger (21) ruptures said sample. The rupturing of the sample does not take place until the maximum clamping pressure on the sample has been attained; in fact, the quantity of glycerin or other hydraulic agent in the cylinder 7 should be so proportioned that the plunger 21 does not even come into contact with the sample until the maximum or approximately maximum clamping pressure is applied to the sample. The pressure exerted by the plunger 21 to rupture the sample is registered in the usual manner and by the usual means.

An opening 56 is provided in the clamp 30 to accommodate the plunger 21 and the portion of the sample that is ruptured or tested. lVhen the high part of the cam 38 rides away from the follower 35, the latter rises with the plunger 32, tripod 31 and clamp 30, and under the influence first of the two springs 27 and 39 and then of the latter spring alone, until said clamp is in its elevated position again. 27 expands, as the cam pressure from above decreases and is finally removed altogether, and raises the table 20 and the plunger 19 into normal position, the plunger 21 having meanwhile settled down again onto the shoulder 24:. By the time the low part of the cam 38 is once more in contact with the follower 35 all parts are in initial position, and ready for the next cycle. The ruptured sample may be removed as soon as it is released by the clamp in rising.

The canractuating mechanism may be stopped and started at each cycle or may be left in motion during the entire time that the machine is in actual use for making tests, the stopping and starting in any event being effected by means of the rod 49 and its handle 50. When the machine as a The spring durable than a rubber diaphragm, of the old Mullen tester type, but lends itself most readily to a construction in which is used resilient clamping means, such as I have herein described.

lVhat I claim as my invention, and desire to secure by Letters Patent, is

1. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, sample puncturing means operated by said resilient means, and means to operate said resilient means.

2. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means operated by said resilient means, and power-driven means to operate said resilient means. I I

3. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, sam

ple-puncturing means operated by said resilient means, and means for operating said resilient means to produce a uniformly-increasing pressure on said sample.

4. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means operated by said resilient means, and means to operate said resilient means.

5. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holdinga sample over said cylinder, sample puncturmg means operated by said resilient means, and meansadapted first to operate said resilient means and therefore to cause said sample-puncturing means to operate.

6. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means operated by said resilient means, and automatic means to operate said resilient means and with the latter said sample-puncturing means.

7. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means operated by said resilient means, and automatic means adapted first to operate said resilient means and then to cause said sample-puncturing means to operate. V

8. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means operated by said resilient means, and -power-driven means to operate said resilient means and with the latter said sample-puncturing means.

9. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, sample-puncturing means operated by said resilient means, and power-driven means adapted first to operate said resilient means and therefore to cause said sample-puncturing means to operate.

10. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means, and means for operating said resilient means, to produce a uniformly increasing-pressure on said sample, and for operating said sample-puncturing means.

11. In a tensile strength tester, a fluid cylinder, resilient means for supporting and holding a sample over said cylinder, samplepuncturing means, and means for first operating said resilient means to produce a uniformly-increasing pressure on said sample, and therefore to cause said samplepuncturing means to operate.

12. A tensile strength tester comprising sample-puncturing means, resilient samplesupporting and clamping means, and means to cause said puncturingmeans to be actively operated with the aid of said clamping means and after the latter has acted to secure a sample to be disrupted by said puncturing means.

13. A tensile strength tester comprising a fluid cylinder, resilient means to support a sample over said cylinder, means, operated by said resilient means, for exerting pressure on said sample to puncture the same, and means, cooperating with said resilient supporting means, for holding said sample while being subjected to said pressure-exerting means.

14. A tensile strength tester comprising a fluid cylinder, sample-disrupting means, resilient supporting and clamping means for holding a sample while being subjected to said disrupting means, and operating means for said resilient means, the displacement of the fluid in said cylinder, by said resilient means when operated, causing, said disrupting means to operate.

15. A tensile strength tester comprising a fluid cylinder, resilient supporting and clamping means for a sample while being tested, sample-puncturing means, and means to operate said resilient means to produce the clamping action and, through the medium of said resilient means and the fluid in said cylinder, cause said puncturing means to act, after a predetermined pressure has been exerted on said sample by the clamping means.

16. The combination, in a tensile strength tester, with a fluid cylinder, a hollow springsupported plunger and table, the former operating in said cylinder, and a disrupting plunger operating in and through said hollow plunger and table, of means to force said spring-supported plunger inwardly in said cylinder, with a sample held between said table and said means, and to cause said disrupting plunger to be forced outwardly,

by the fluid in said cylinder, to rupture said sample.

17. The combination, in a tensile strength tester, with a fluid cylinder, a hollow springsupported plunger and table, the former operating in said cylinder and provided with an interior support, and a disrupting plunger operating in and through said hollow plunger and table and receivable on said support, of means to force said spring-supported plunger inwardly in said cylinder, with a sample held between said table and such means, and to cause said disrupting plunger to be forced outwardly, by the fluid in said cylinder, to rupture said sample.

18. The combination, in a tensile strength tester, with a fluid cylinder, a hollow springsupported plunger and table, the former operating in said cylinder, and a puncturing plunger operating in and through said hollow and table, of a recessed clamp, and means to actuate said clamp into contact with said table, and to force said hollow plunger, against the resistance of its spring, into said cylinder, and cause said puncturing plunger to emerge from said table.

19. The combination, in a tensile strength tester, with a fluid cylinder, a hollow springsupported plunger and table, the former operating in said cylinder, and a puncturing plunger operating in and through said hollow plunger and table, of a recessed clamp, adjustable means to support said clamp in operative position relative to said table, and means to actuate said clamp into contact with said table, and to force said hollow plunger, against the resistance of its spring, into said cylinder, and cause said puncturing plunger to emerge from said table.

20. The combination, in a tensile strength tester, with a fluid cylinder, a hollow plunger and table, the former operating in said cylinder, a spring arranged in supporting relation to said plunger and table, and a puncturing plunger operating in and through said hollow plunger and table, of a reciprocable rod, a recessed clamp connected with said rod and being in operative position relative to said table, and means to actuate said rod.

21. The combination, in a tensile strength tester, with a fluid cylinder, a hollow plunger and table, the former operating in said cylinder, a spring arranged in supporting relation to said plunger and table, and a puncturing plunger operating in and .through said hollow plunger and table,of a

reciprocable cam-operated rod, and a re cessed clamp connected with said rod and being in operative position relative to said table.

22. The combination, in a tensile strength tester, with a fluid cylinder, a hollow plunger and table, the former operating in said cylinder, a spring arranged in supporting relation to said plunger and table, and a puncturing plunger operating in and through said hollow plunger and table, of a reciprocable rod, a recessed clamp connected wlth said rod and belng 1n operatlve relation to said table, a worm-driven shaft, a

cam on said shaft, and means to cause said rod to be operated by said cam.

23. The combination, in a tensile strength tester, with a fluid cylinder, a hollow plunger and table, the former operating in said gage and disengage said shaft to and from said mechanism, and means to operate said clutch.

24. The combination, in a tensile strength tester, with a fluid cylinder, of a hollow plunger and table, the former operating in said cylinder and being open at the base, a

spring arranged to support said plunger and table, and a puncturing plunger operating in and through said hollow plunger and table.

25. The combination, in a tensile strength tester, with a fluid'cylinder, of a hollow plunger and table, the former operating in said cylinder and being open at the base, a spring arranged in supporting relation to said plunger and table, a puncturing plungeroperating in and through said hollow plunger and table, and means to support said puncturing plunger when in inactive position. a

26. The combination, in a tensilestrength tester, with a fluid cylinder, of a hollow plunger and table, the former operating in said cylinder, being open at bottom, and having an interior supporting member, a spring arranged in supporting relation to said plunger and table, and a puncturing plunger operating in and through said hole low plunger and table and adapted when inactive to rest on said support.

27. The combination, in a tensile strength tester, with a fluid cylinder, of a hollow plunger having a flangeat the top to form a table, said plunger operating in said cylinder, a spring interposed between said cylinder and said flange, and a puncturing plunger-operating in and through said hollow. plunger.

SAMUEL N. SENNA. Witnesses F. A. CUTTER, A. C. FAIRBANK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

